vs code dart analyzer 不启动 ,找不到类的定义 解决方法

To fix, just give the Dart extension an explicit reference to your SDK installation(s) using the extension settings ([Ctrl + ,], type ‘Dart:’) or by directly editing settings.json ([Ctrl + Shift + P], type ‘settings.json’, [Enter]).

If you have both Flutter and the full Dart SDK installed, add both listings:

If you have only one installed (most commonly just Flutter), you can just add that one:

 

来自: https://stackoverflow.com/questions/54488236/vscode-dart-analyzer-stopped-recognizing-flutter-dart-code

 

 

flutter globalkey 的用法

文档写道,globalkey的作用是:

GlobalKeys have two uses:

a) they allow widgets to change parents (注意是parent , 怎么判断一个widget是不是另一个的parent ? )anywhere in your app without losing state,

or they can be used to access information about another widget in a completely different part of the widget tree. An example of the first scenario might if you wanted to show the same widget on two different screens, but holding all the same state, you’d want to use a GlobalKey. (不是parent似乎也可以)

 

flutter bloc pattern

  • 文字教程

https://www.raywenderlich.com/4074597-getting-started-with-the-bloc-

pattern

 

  • 概念

This architectural contract is not too dissimilar from classical MVC. The UI/Flutter layer can only talk to the BLoC layer. The BLoC layer sends events to the data and UI layers and processes business logic. This structure can scale nicely as the app grows.

 

Streams, like Futures, are provided by the dart:async package. A stream is like a Future, but instead of returning a single value asynchronously, streams can yield multiple values over time. If a Future is a value that will be provided eventually, a stream a series of values of that will be provided sporadically over time.

 

 

 

同时或者近似同时播放多个animation , 以及怎样与flr互动

  • 互动参考:

https://medium.com/filledstacks/better-animations-in-flutter-using-flare-an-experiment-ddcb35ab0650

 

 

  •  mixin , 也就是把2个动画混合 。  参考 :

https://github.com/2d-inc/Flare-Flutter/tree/09b307c113e2b10c7a7bcc07ca9d2f50aff94cb3/example/penguin_dance

 

但是源代码不能编译, 需要把 implement 改为  with  , 此答案来自:

https://github.com/xuelongqy/flutter_easyrefresh/issues/78

 

 

 

wow classic pvp macro

  •  warrior

 

 

python 数值分析